Apparatus for the distillation of a liquid through a gas permeable wall



Jan. 29, 1963 J. D. ELAM 3,075,391

APPARATUS FOR THE DISTILLATION OF A LIQUID THROUGH A GAS PERMEABLE WALLFiled Jan. 3, 1958 I 8 I l I I i FIG. I

T I; H 8 i: H I I: I: 5: I I H 1| I II II II H II l n FIG. 2 0

INVENTOR Joseph Donald Elam ATTORNEY United States This inventionrelates to the distillation of liquids and is applicable to theproduction of potable water from saline solutions such as sea water.

This device makes use of the principle that paper containers for hotliquids permit the passage of water vapor through their walls. Thisvapor or free water molecules may be condensed on a cool surface if theouter wall of the paper container and the cool surface are suitablyproximate and the air and space between the two surfaces re properlycontrolled.

e device consists of metal chambers having a V ape as seen in side view(FIG. 1) and rectangular as seen in top plan view (-FIG. 2). The wallsof the metal chambers define the cool plates or condenser means for theapparatus. The container for the liquid to be distilled includes rigidwalls 1 formed of paper stock. This paper stock is placed inside themetal containers with the rigid paper walls of the paper containerparallel to the cool plates by alternately rolling the paper over rod 5and under rod 9 which are employed for spacing the rigid paper stockfrom the cool plates. A frame 8, together with a gum rubber edgingdeposited on the rigid paper stock seals the paper container watertight.

A perforated pipe 6 is provided for spraying coolant on the cool plate,While a shaped perforated pipe 4 is employed for introducing hot liquidto the paper chamber. The pipe 4 also acts as a support for a cover 3.The cover 3 is formed with a lens that is shaped as a section of acylinder, and can be used during periods of sunlight to focus the raysof the sun on the filter subject to maintain a temperature mostexpeditions to the distilling process. An electric immersion-type heaterelement 10 may be used for temperature maintenance in the absence ofsunlight. A chamber 7 is located at the lowermost end of the metalchamber and is provided for the collection of liquid which condenses onthe cool plates.

This invention is particularly applicable to the distillation of seawater at sub-boiling point temperatures. Sea water may be used as thecoolant when unheated and as the distillation subject when heated.

Dimensions are not critical except between the gas permeable wall andthe cool plate. This distance probably must not exceed one inch.

Since the formed paper chambers are enclosed the residue of thedehydration or deliquefying process is recoverable at various stages ofconcentration.

I claim:

1. Apparatus for distilling a pure liquid from an imatent 0 pure liquidat atmospheric pressure and at temperatures below the boiling point ofthe impure liquid, comprising an enclosed space containing a pool of theimpure liquid therein, said enclosed space having at least a portion of5 its Walls formed of a relatively rigid liquid-proof gas permeablematerial having the pool of impure liquid in contact therewith, anon-absorbent cooling surface located exteriorly of each gas permeablewall of said enclosed space, each said cooling surface enclosing a majorportion of the adjacent gas permeable wall and spaced in proximitythereto to form an unobstructed passage therebetween, a collectingchamber located below said passage and communicating therewith adaptedto receive the pure liquid, means for increasing the temperature of theimpure liquid to a temperature less than the boiling point thereof, andmeans for cooling the exterior surfaces of said cooling surfaces,whereby vapor passing through said gas permeable walls condenses on saidcooling surfaces as the pure liquid and flows downwardly by gravity intosaid collecting chamber.

2. Apparatus for distilling a pure liquid from an impure liquid atatmospheric pressure and at temperatures below the boiling point of theimpure liquid, comprising a plurality of enclosed spaces each containinga pool of the impure liquid therein, said enclosed spaces having theirside walls formed of a continuous strip of a relatively rigid liquidproof gas permeable material extending from one enclosed space to thenext, the pools of impure liquid being in contact therewith, anon-absorbent cooling surface located exteriorly of each gas permeableside wall of said enclosed spaces, said cooling surfaces enclosing amajor portion of said gas permeable side walls and spaced in proximitythereto to form an unobstructed passage between each gas permeable sidewall and its adjacent cooling surface, a collecting chamber locatedbelow said passages for each enclosed space and communicating with saidpassages and adapted to receive the pure liquid therein, means forincreasing the temperature of the impure liquid to a temperature lessthan the boiling point thereof, and means for cooling the exterior surfaces of said cooling surfaces, whereby vapor passing through said gaspermeable walls condenses on the interior surfaces of said coolingsurfaces as the pure liquid and flows downwardly by gravity into saidcollecting chambers.

References Cited in the file of this patent UNITED STATES PATENTS1,577,653 Nugent Mar. 23, 1926 1,881,041 Benjamin Oct. 4, 1932 2,445,350Ginnings July 20, 1948 2,712,386 Jones et al July 5, 1955 2,793,174Smith May 21, 1957 2,881,116 Siegfried Apr. 7, 1959

1. APPARATUS FOR DISTILLING A PURE LIQUID FROM AN IMPURE LIQUID ATATMOSPHERIC PRESSURE AND AT TEMPERATURES BELOW THE BOILING POINT OF THEIMPURE LIQUID, COMPRISING AN ENCLOSED SPACE CONTAINING A POOL OF THEIMPURE LIQUID THREIN, SAID ENCLOSED SPACE HAVING AT LEAST A PORTION OFITS WALL FORMED OF A RELATIVELY RIGID LIQUID-PROOF OF MEABLE MATERIALHAVING THE POOL OF IMPURE LIQUID IN CONTACT THEREWITH, A NON-ABSORBENTCOOLING SURFACE LOCATED EXTERIORLY OF EACH GAS PERMEABLE WALL OF SAIDENCLOSED SPACE, EACH SAID COOLING SURFACE ENCLOSING A MAJOR PORTION OFTHE AJACENT GAS PERMEABLE WALL AND SPACED IN PROXIMITY THERETO TO FORMAN UNOBSTRUCTED PASSAGE THEREBETWEEN, A COLLECTING CHAMBER LOCATED BELOWSAID PASSSAGE AND COMMUNICATING THREWITH ADAPTED TO RECEIVE THE